// console.time("timer");
// for (var i = 0; i < 10000; i++) {
//     console.log(i);
// }

// console.timeEnd("timer");

// for (const key in document) {
//     console.log(key, document[key]);
// }

var el = document.querySelector('#demo');
console.log(el.nodeType, el.nodeValue);
console.log(el.parentNode.nodeName);
el.setAttribute('style', 'color:red;text-align:center');
var p = document.createElement("p");
document.body.appendChild(p);
p.appendChild(document.createTextNode('这是使用DOM添加的内容'));
p.innerHTML = "<b>这个内容</b>又被替换了";
p.innerText = '<b>这个内容</b>又被替换了';

data = {
    core_id: "18",
    country: "Netherlands",
    guide: "",
    nid: "297816"
};
console.log(data);
console.log(JSON.stringify(data));
console.log(typeof JSON.stringify(data));
console.log(typeof data);

str = '{"core_id":"18","country":"Netherlands","guide":"","nid":"297816"}';
console.log(JSON.parse(str));
